• Structural Engineering and Mechanics
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• v.74 no.5
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• pp.577-588
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• 2020

A unified solution is presented for the buckling analysis of rectangular laminated composite plates with elastically restrained edges. The plate is subjected to biaxial in-plane compression, and the boundary conditions are simulated by employing uniform distribution of linear and rotational springs at all edges. The critical values of buckling loads and corresponding modes are calculated based on classical lamination theory and using the Ritz method. The deflection function is defined based on simple polynomials without any auxiliary function. The verifications of the current study are carried out with available combinations of classic boundary conditions in the literature. Through parametric study with a wide range of spring factors with some classical as well as some not classical boundary conditions, competency of the present model of boundary conditions is proved.

• Journal of Korean Classical Literature and Education
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• no.39
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• pp.41-66
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• 2018

This paper investigates how narrative folk songs have been transmitted and enjoyed through literature data and field research, and discusses their educational significance. Narrative folk songs have changed from songs that were enjoyed by common women to songs enjoyed by upper class men according to the times. They have ranged from tragic songs lamenting hardships to comic songs that relieve oppression, depending on the performance situation. Moreover, narrative folk songs have been enjoyed through media transmission beyond traditional custom. Narrative folk songs have not been enjoyed in one fixed way, but rather in various ways depending on the situation, so they have functioned to enable common women, who are their main singers, to share emotions, communicate, and maintain their community. Therefore, in literature education, narrative folk songs can be used as very appropriate materials for learners to reflect on themselves, communicate with others and contribute to desirable community life. By experiencing the various ways of enjoying narrative folk songs, learners will be able to grow into subjects who actively solve their own problems and those of their communities.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.661-674
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• 2018

This paper studies how the audience perceives the types of classical performances in their performance choice, analyzes its effects on performance invigoration, and investigates how such an audience perception affects the marketing application of performance on the supply side. For this, based on data of performance programs delivered in five representative concert halls for last three years as well as the classification of previous literature, we classified performance types into five categories such as Authentic classic, Omnibus, Lecture, Crossover and Mixture type. And then, we surveyed the audience of classical music. From statistical analyses, we found first that the audience perceives the types of classical performances and utilizes their perception as an element in choosing performances. Second, the perception of classical performance types has significant effects on audience development and progress in circumstances of high audience acceptance and satisfaction. Finally, this result confirms that suppliers can employ this audience perception as a marketing strategy by setting target audience based on such perception.

• Korean Journal of Acupuncture
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• v.28 no.1
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• pp.157-169
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• 2011

Objective : Nine classical needles have been recorded in oriental medical classics as a diversified instrument for acupuncture to treat patients with various symptoms. Recently, it has suggested that doctors didn't make full use of acupuncture and that poor understanding of the nine needles has caused the lack of usage. Methods : It has studied bibliographically about the conformation including a length & shape and application & usages of the nine classical needles presented in oriental medical classics. Results : Chamchim (shear needle) has 1.6 chon (寸) length, sharp apex treating fever in the head and trunk; Wonchim (roun-pointed needle) has 1.6 chon, eggshaped apex treating disease of flesh by massaging with it; Sichim (spoon needle) has 3.5 chon, thick body with round sharp apex treating weakness of Qi; Bongchim (lance needle) has 1.6 chon, a triangled apex treating chronic disease with bleeding; Pichim (stiletto needle) has 4 chon, razor sharp applying to surgery of big pus; Wonlichim (round-sharp needle) has 1.6 chon, thin body, sharp apex treating acute arthralgia syndromes; Hochim (filiform needle) has various lengths which treats various disease of meridians and organs; Jangchim (long needle) has 7 chon, sharp apex treating chronic arthralgia syndromes in deeper place of body; Daechim (large needle) has 4 chon, nail like apex applying to excrete artheredema in joints. Conclusions : The conformation of nine classical needles has been changed from those recorded in oriental medical classics since it was developed. However, the usage of nine classical needles has remained the same. Therefore it is considered that intrinsic attribute of the nine needles has preserved even though the conformation of nine classical needles has changed.

• Journal of Korean Library and Information Science Society
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• v.30 no.3
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• pp.365-384
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• 1999

This papepr analyzes the causes of the crisis of Library and Information Science and proposes an management program of LIS. To overcome this crisis, the author made an management program by solidifying LIS as a science and enlarging research fields. To solidify LIS as a science, it can be helpful to translate classical literature on LIS into Korean for universality, and to base our own history and culture for individuality. Enlarging research fields of LIS will help to enrich theories and to develop new jobs. She suggests archives, local studies collection, preservation and literature on North Korea as additional research fields by example.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2107-2113
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• 2014

Particle filtering (PF) has shown its outperforming results compared to that of classical Kalman filtering (KF), particularly for highly nonlinear problems. However, PF may not be universally superior to the extended KF (EKF) although the case (i.e. an example that the EKF outperforms PF) is seldom reported in the literature. Particularly, PF approaches show degraded performance for problems where the state noise is very small or zero. This is because particles become identical within a few iterations, which is so called particle impoverishment (PI) phenomenon; consequently, no matter how many particles are employed, we do not have particle diversity regardless of if the impoverished particle is close to the true state value or not. In this paper, we investigate this PI phenomenon, and show an example problem where a classical KF approach outperforms PF approaches in terms of mean squared error (MSE) criterion. Furthermore, we compare the processing speed of the EKF and PF approaches, and show the better speed performance of classical EKF approaches. Therefore, PF approaches may not be always better option than the classical EKF for nonlinear problems. Specifically, we show the outperforming result of unscented Kalman filter compared to that of PF approaches (which are shown in Fig. 7(c) for processing speed performance, and Fig. 6 for MSE performance in the paper).

• Advances in nano research
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• v.6 no.3
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• pp.219-242
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• 2018

In this study, static bending of an edge cracked cantilever nanobeam composed of functionally graded material (FGM) subjected to transversal point load at the free end of the beam is investigated based on modified couple stress theory. Material properties of the beam change in the height direction according to exponential distributions. The cracked nanobeam is modelled using a proper modification of the classical cracked-beam theory consisting of two sub-nanobeams connected through a massless elastic rotational spring. The inclusion of an additional material parameter enables the new beam model to capture the size effect. The new non-classical beam model reduces to the classical beam model when the length scale parameter is set to zero. The considered problem is investigated within the Euler-Bernoulli beam theory by using finite element method. In order to establish the accuracy of the present formulation and results, the deflections are obtained, and compared with the published results available in the literature. Good agreement is observed. In the numerical study, the static deflections of the edge cracked FGM nanobeams are calculated and discussed for different crack positions, different lengths of the beam, different length scale parameter, different crack depths, and different material distributions. Also, the difference between the classical beam theory and modified couple stress theory is investigated for static bending of edge cracked FGM nanobeams. It is believed that the tabulated results will be a reference with which other researchers can compare their results.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.249-257
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• 2011

In this paper, an systematic approach is presented, in which the mixed variational theorem is employed to incorporate independent transverse shear stresses into a classical higher-order shear deformation theory(HSDT). The HSDT displacement field is taken to amplify the benefits of using a classical shear deformation theory such as simple and straightforward calculation and numerical efficiency. Those independent transverse shear stresses are taken from the fifth-order polynomial-based zig-zag theory where the fourth-order transverse shear strains can be obtained. The classical displacement field and independent transverse shear stresses are systematically blended via the mixed variational theorem. Resulting strain energy expressions are named as an enhanced higher-order shear deformation theory via mixed variational theorem(EHSDTM). The EHSDTM possess the same computational advantage as the classical HSDT while allowing for improved through-the-thickness stress and displacement variations via the post-processing procedure. Displacement and stress distributions obtained herein are compared to those of the classical HSDT, three-dimensional elasticity, and available data in literature.

• Journal of Power Electronics
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• v.13 no.6
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• pp.939-954
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• 2013

The Direct Torque Control (DTC) technique for Permanent Magnet Synchronous Motors (PMSM) is receiving increased attention due to its simplicity and robust dynamic response when compared with other control techniques. The classical switching table based DTC results in large flux and torque ripples in the motors. Several studies have been reported in the literature on classical DTC. However, there are only limited studies that actually discuss or evaluate the classical DTC. This paper proposes, novel switching table / DTC methods for PMSMs to reduce torque ripples. In this paper, two DTC schemes are proposed. The six sector and twelve sector methodology is considered in DTC scheme I and DTC scheme II, respectively. In both DTC schemes a simple modification is made to the classical DTC structure. The two level inverter available in the classical DTC is eliminated by replacing it with a three level Neutral Point Clamped (NPC) inverter. To further improve the performance of the proposed DTC scheme I, the available 27 voltage vectors are allowed to form different groups of voltage vectors such as Large - Zero (LZ), Medium - Zero (MZ) and Small - Zero (SZ), where as in DTC scheme II, all of the voltage vectors are considered to form a switching table. Based on these groups, a novel switching table is proposed. The proposed DTC schemes are comparatively investigated with the classical DTC and existing literatures through theory analysis and computer simulations. The superiority of the proposed DTC method is also confirmed by experimental results. It can be observed that the proposed techniques can significantly reduces the torque ripples and improves the quality of current waveform when compared with traditional and existing methods.

• Journal of Korean Classical Literature and Education
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• no.16
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• pp.5-27
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• 2008

It is not a simple topic how let the modern readers read the past literature in the these days of digital. But even though the changes of the times, we must not let 'the paper-books(the thing written with letters)' disappear because of 'the audio-visual texts(the thing made with digital media as drama-opera, animated cartoon, animated image)'. The Electronic medias should be used so as helping for us to understand contents of the paper-books. Because of them, the paper-books must not be expelled. It is no need certainly for the reading materials to be made with Paper-books. For example, the electronic-books in order to read also would not become problems. Moreover, the electronic-books to be made with various electronic media can also provide the audio-visual materials for readers well to understand contents of the books. For that reason, the electronic-books would be helped to read effectively. Besides after reading the original texts, the readers to try the 'rewriting', with using the meanings for oneself to get from the texts would be able to make a synopsis or story-telling for other art performances. These works are things positively to be stimulated, because of giving the achievement motivations to the readers. To conclude, the audio-texts reading and the visual-texts reading should be developed so that the paper-books to be revitalize. And though the modern readers dislike to read the paper-books, We should try to make the audio-visual texts base on the paper-books. Therefore the paper-books and audio-visual texts are inter-complementary relationships, not competitive relationships.